Pneumatic engine.



No. 848,255. PATENTED MAR. 26, 1907.

E. LEICHTER. PNBUMATXU ENGINE. APPLICATION FILED JAN. 24, 1906.

y 'y M 5| al V5 l' 5 I 'l I l m i N` tw l d i i F /'N (VHN I m r-Q' gif rE-: I I* l* l e m l im? w l1 by 'r 11W Iv 1 K3 m i' l N L] Y a r I Witnesses: Inventor [n1 W uu QQ mf m- 5' Mchn Attorney lT will "lll" llt t onirica,

, or Nuvi-uni ti'ri', innnfonxni, AVAissioxou or onn- PNEUMATIC ENGINE No, y 848,255.

Arplicatiou tiled January 24,

T @ZZ whom, zt may con/cerro: .y

Be it lmownthat 1, llnwnnu Lnien'rnn, a citizen of the United States, residing in Nevada City, Nevada county, lalifornia, (postoilice address Box 464, Nevada (.ity, Californien) have invented certain new and useful Improvements in Pneumatic Engines, of which the following a specification.

This invention,` pertaining to improvements in pneumatic engines designed for general hammering purposes will bf n" dily understood from the following des tion, taken in connection with the accowA nying drawing, which is a longitudinal `se 'lon of a pneumatic engine embodying my invention in a hand-held device of the class usually spoken of as neumatic tools.7

Wlii e l refer to my invention as a pneumatic engine, it should he explained that some or all of its features are adapted forem- -ployment with any working fluid, For convenience of expression I will, however, 'con- 4 fine myself in the resent description to airv as the working fluid; but it is to be under- 2 5` stood thatl such fluid is merely typical.

In the drawing, 1 indicates the cylinder, which has a maj or and minor here; 2, the cyl-` inder-head, which is a hollow flanged plug separahly inserted in the heel end of the cylinder; 3, the major bore of the cylinder; `f1, the-minor bore of the cylinder; 5, the shell, which is a cylindrical sleeve snugly inclosing the cylinder structure; G, the tool-socket, sup.- ported in the'outer end of the shell with its axis coincident with that of the cylinder 7, the tool-shank, on which the piston is to hammer; 8, the handle, secured to the rear end of the general structure; Q, the air-inlet, adapted to receive connection from a supply-hose; 10, inletassage leading through the liandle from t e inlet to the cylinder-head 2 11, the throttle, mounted on the ,handle and serving to control the inlet of air to the working parts of the structure; 12, a coupling-nut uniting` the handle to the shell and serving also to hold the cylinder-head to place; 13, a longitudinal groove in thc 'periphery of the cylinder structure, an outer wall for this groove being formed by the interior surface of the shell, there being a circumferential series of these grooves in order to provide a suliiciency of air-passage, the present description, however, being confined to a single groove orpasn in Specification of Letters Patent.

190s. serial No. 297,544;

Patented March 26, 1907.

sage; 1.4, radial ports through the wall of the cylinder-head to lead the supply of air outwardly from. the hollow of the cylinder-h.':ad, there being one of these ports for each of the grooves 13 15, a radial port through the wall of the cylinder registering with port 14- and serving to place passage 13 always in free communication with the air entering from the inlet; 16, an annular' enlargement of the major here of the cylinder, the major here of the cylinder having a normal diameter to thel front and rear of this enlargement; 17, an annular shoulder in the cylinder, forming the rear wall of the enlargement 16; 1S, an annular shoulder in the cylinder, forming the front wall of the enlargement 16; 19, an annular enlargement in the major bore of the cylinder forward of the enlargement 16; 20, the annular shoulder forming-the rear wall of the enlargement 19 5 21, the annular shoulder forming the front Wall of the enlargement 19;

V22, a port through the cylinder-wall, placing enlargement 19 always in free communication with passage 13; 23, the shoulder forining the front wall of the major bore of the cylinder; 24, a port through the cylinder-- wall at the forward portion of the major here of the cylinder, this port placing the forward and of the maj or here of the cylinder always 'iin free communication with passage 13; 25,-

the piston, considered as a whole, the same serving as the striking-hammer and having a major and a minor vdiameter adapted to lit the differential cylinder, the piston having a central cavity open at its rear to lighten the piston and serve as an air-passage; 26, the forward minor diameter portion of the pisv ton; 27, the rear major diameter of the piston; 28, a neck forming are/duction of the major diameter of the piston at an intermediate point in its length 2U, the shoulder of the piston, forming the rear Wall of this neck; 30, the shoulder of the piston forming the front wall of the neck; 31, a radial port in the rear portion of the piston, permitting air entering this port inwardly te reach the rear end of the cylinder; 32, a similar port in the forward portion of the maj or diameter of the piston; 33, a similar port in the minor diameter of lthe piston, the ports 31, 32, and. 33, thus far described each in the singular, being repeated at circumferential intervals around the piston in order to increase the airway; 34,

IOC

the exhaust-outlet through the forward end of 'the general structure; 35, the forward chamber of the cylinder structure forward of tl e minor .bore of the cylinder, and -36 the forwardly-presenting sl'ioulder of the piston at the juncture of its minor and major diam eters.

The eneine will be recognized as being of the valveess type-that is to say, without ot ier valves than as furnished by its piston. ihen sir is permitted torenter .the structure, its full pressure is in passage i3 and free to exert itself` through 'ports 22 and 24. When the" partsare in the position shown inthe drawing, the piston is the rear end of its stroke, subject to trifling variations. The air under iuli pressure passes freely through erts and and. through ports 24 and 33 and through the cavity of the piston and has ee access to the rear end of the cylinder, iuil pressure, therefore, acting forwardly on. the major area of the piston, At the same ie the full pressure is on the annular area o the piston'represented by shoulder 36. 'I "ne consequence is that full pressure, tending to drive the piston forward, is acting on the major areaot the piston, while full pressure, 'tending to resist the forward motion of the piston, is acting on the annulus 35, or, to state it otherwif there is a forward urgency on the ton represented by lull'pressure on an. area ,c resented by its minor (,liaxneter.

The air no n to the raar end of the cylinder gol through the two ports 32 and 33, and umh vLe influence of this air the piston is starled ori a state oi rest and driven forward. L lly in advance of the piston the port to shoulder i7 and port he@ r sass shonhler 2S, port 35) thus bee" e close, while port 3l begins to open. ortly port 33 will be entirely el' rt 5i 'vill be entirelyopen. ln the i shoulder 30 ol the piston will .har we l beyond shoulder 2() of the air 'trom port 22 may flow to port 3i. fit the 'iirst stage the to the cylinder was through two ports and 32 and correspondingly liti-eral. the eccoti-id port 33 has out et action and port 31 substi- Si smaller than port 33, the r. beine that while the Ydow is still thmugghta ports one of the ports of the pair is shia-iler than was before the the ow having; therefore been gradually recylini ler, an il tl rrr inliow ed upon its atrire stroke` As the piston further advances port 32. overruns shoulder 21 and becomes closed, whereupon the flow of airto the cylinder is through small port 3l alone, which is amply sul'licient to carry the piston forward under its acquiredenergy, due to the more liberal iniiow of air at the earlier stages. In the ueed in liherality after the piston has startseaass y continued advance of tne piston port 31 over- 6 5 runs shoulder 18, whereupon all iniiow of air to the cylinder is cut oi, the piston now ad vancing as the result of .expanison of the air and the acquired momentum ol. the piston. Later the port 33 opens to chamber 35 and 7o thence to outlet 34, thus exhausting the cylinder, the stroke being com leted and the blow struck under the eiiect o momentum of the piston.' The piston strikes its blow and rebounds and starts upon its return stroke, urged by its rebounding momentum and by the air-pressure against annulus 36. The exhaust through port 33 becomes out off, the air con-fined behind the piston becomes compressed to form a cushion, port 31 admits 80. working pressure to thecushioning air, and

in due course the original condition for start-v ing on a new active stroke is reached.

In practice I find the machine to be eX- eeedingly efficient. Its blows are foroeful, its air economy satisfactory to a superior degree,it is not subject to short strokes,the piston will not cease itsimotibn in any position while the pressure is on, and the piston can be started into motion from any position in 9o which lit may have come to rest with the pressure off.

i claim- A pneumatic engine comprising a cylinder having a major bore and a minor bore and having a first annular enlargement in the major bore contiguous to the minor bore and having a second annular enlargement `in the major bore at a further distance from the minor bore and having a third annular en roo largement in the major bore at a still further distance from the minor bore, the first and second oi' said annular enlargements being in free communication with the source of Huid supply, and a two-diameter piston fitting 1o 5 said bore and having the extremity of, its smaller portion projeotinfr out of the' minor bore of `the cylinder, said piston lhaving an cavity extending within i from its larger end to a point near its s aller end, iro said piston being provided with set of ra dial ports placing its axialcavity in communication with the irst of the annular enlargY miente of the major bore of the cylinder an having a second set of radial ports plac- 'I 15 ing said cavity at the same time in communication with the second of said annular enlargements yand having a third set of radial ports leading from said'cavity and closed by the inwall of the major bore of the cylinder when the first two 4sets of ports are in said relationship with the first and second annular bores of the cylinder, combined substantially as set forth.

.EDWARD LEinrnn. Nitnessesi H. C. CLOUDMAN, J. C. CAMPBELL. 

